Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

No, stainless take-off for wideband sensor pre-turbo, so that you don't pressurise the sensor and damage it.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

The actual sensor ports are in line with the incoming pipe that is 4mm bore.

The sensor is 15mm diameter. The bore of the chamber is 21mm and the downstream pipe bore is about 13mm.

There is approx 12mm of chamber before going to the smaller diameter.

It will get hot enough as the outlet pipe is going to be welded to the bend on the turbo outlet.

I've made the other one now.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I don't know if you intend to put it on the same exhaust as the one you were using before but if it's the case and you still have the sensor bungs on it, you could put one sensor in the original bung and one on this new chamber and compare readings.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Need to add a couple of bosses to the manifold near the flanges and make up the pipes.

I think I'll make up the actuator bracket first just to ensure nothing clashes.

Off to watch the Big Pricks now though.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

On 20th Jun, 2009 miniminor63 said:I thought this was for the sidemount turbo engine?

This one is for the 998 Turbo.

I'll be doing something similar for the side mount turbo in the Miglia if this works OK.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I suppose that the inners are going to be a few revs behind the outers. The logs will show up if there is an issue.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

On 21st Jun, 2009 stevieturbo said:Might have been better dumping them further down the exhaust, so there is less chance of the ex-tubine gasses shooting up the tube, contaminating your sample.

Or better still, vent the post sensor to atmos

Good point.

That may well happen at low load. I'm hoping that under boost there will be enough pressure to keep things moving in the right direction.

I'm planning on having a proven setup in NA mode, so that I'll only need to be concerned with AFRs under boost.

Can always modify it later.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

You guys are so far ahead of me I dont really follow these threads, but can you tell me why you want to move the oxygen sensor away from the manifold instead of just putting it in a boss close to the turbo outlet ?.Is it because you want to sample for each exhaust port ?.

Yes, with port injection, the inner and outer cylinders run at different AFRs unless the timing of the injection is precise, so we need to measure inner and outer AFRs separately.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

On 21st Jun, 2009 stevieturbo said:Might have been better dumping them further down the exhaust, so there is less chance of the ex-tubine gasses shooting up the tube, contaminating your sample.

Or better still, vent the post sensor to atmos

Good point.

That may well happen at low load. I'm hoping that under boost there will be enough pressure to keep things moving in the right direction.

I'm planning on having a proven setup in NA mode, so that I'll only need to be concerned with AFRs under boost.

Can always modify it later.

Given the small diameter of the feed tubes ( for obvious reasons ), I think the exhaust gases exiting the turbo, could shoot straight up the tube. More so as the tubes are almost pointing at the turbine exit.
There simply wouldnt be enough volumne of gas at the higher pressure to resist it.

Even if the tubes were cut/welded in at an extreme angle....

In fact at an angle like some of the crankcase evac systems use, so that it actually tends to draw any gases into the exhaust stream.

Ideally the two pipes would join the downpipe after the join but that would be a fabrication and installation nightmare.

Let's see if this works. If this doesn't show variation in AFR between the inner and outer cylinders, then I shall have to reconfigure it.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

i think both paul and steve are right ,at low rpm i can see steves scenario playing out ,particularly between pulses ,and once the turbo creats some back pressure then it changes around to reading as it should..

fitting a tap in the big return that could be adjusted ,would ,perhaps make it a bit adjustable .